1. Field of the Invention
This invention relates to a foldable mechanism, and more specifically, to a foldable mechanism for a playpen.
2. Description of Prior Arts
A wide variety of playpens, have been designed, developed, and commercialized for many years. One of these designs is that the playpen may be folded for storage.
A well known foldable playpen, as shown in FIG. 1, uses a foldable structure 1, comprising a coupling element 2 having a substantially U-shaped cross section; a pair of hollow rods 3 each having therein an engaging element 4 which may extend or retract with respect to the rods through a spring 5, and pivotally screwed to the coupling element 2 by a screw 6; a fixed block 7 secured in the coupling element 2, having a cutout 8 for engaging with the engaging element 4; and a press-down element 9 positioned below and slidably connected to the fixed block 7 for disengaging the engagement between the engaging element 4 and the fixed block 7 when the press-down element 9 is pressed down, or biased, with respect to the fixed block 7 by an external force. When the playpen is in an unfolded condition, the rods 3 are in a horizontal orientation with the engaging element 4 being engaged with the cutout 8 of the fixed block 7. When the playpen is in a folded condition, the press-down element 9 is pressed to disengage the engaging element 4 from the fixed block 7, such that the rods 3 may pivot to a vertical orientation.
In the prior art stated above, the foldable structure uses many parts, which not only complicate the structure but also increase the cost thereof.
Further, in the prior art, most of the parts, such as the fixed block, the press-down element, and the engaging elements, are made of, for example, plastic, which will further increase the manufacturing cost.
Therefore, a foldable playpen that uses few parts and is less expensive to manufacture would be very desirable.